- Children who are diagnosed with brain tumors known as high grade gliomas or diffuse intrinsic pontine gliomas are generally treated with radiation therapy and chemotherapy. However, these tumors are very difficult to cure, and the tumor frequently begins to grow again even after treatment or surgery. Researchers are interested in determining whether the anticancer drug lenalidomide, which has been used to treat other aggressive types of cancer, is a safe and effective additional treatment for children who are scheduled to receive radiation therapy to treat high grade gliomas or diffuse intrinsic pontine gliomas.